day = ID for calendar date
obs = observation number
week = week of test
week_d = week of test with decimals
raw_error = change in chronometer’s deviation from UTC between observations
daily_rate = chronometer rate (sec/day)
hrs_bw_meas = hours between measurements 
R = power reserve (hrs)
T = Temperature (°C)
H = humidity (g/m^3) 
P = pressure (hPa) 
T_max = maximum temperature (°C)
T_min = minimum temperature (°C)
fold = cross-validation fold 
lagged_rate = rate in previous period
